Utility of telephone company records for epidemiologic studies of cellular telephones.

Funch DP, Rothman KJ, Loughlin JE, Dreyer NA,

Epidemiology 7(3):299-302, 1996

We conducted a survey of over 5,000 telephone users who were customers of one
large cellular telephone company covering four major geographical areas. Our primary goal was to
assess the utility of ascertaining information on telephone
use and type from telephone company records. We compared information from
3,949 respondents with corresponding data from company billing records. We found
that 48% of the account holders were sole users, and 69% were the primary user,
meaning that they accounted for at least 75% of the use.

Respondent reports of
amount of telephone use were highly correlated with data on the billing record
(r = 0.74). Respondent reports of telephone type were similarly correlated with
data from the manufacturer (r = 0.92).

We also inquired about telephone holding
patterns, since these have implications for exposure. Most users reported favoring one side of
the head when using the telephone, but the side of the head used was not strongly associated with
handedness.